Here's how it works:

* Heat from the Earth's core: The Earth's core is incredibly hot, and this heat is transferred outward into the mantle.

* Convection currents: The heat causes the mantle to become less dense, and it rises. Cooler, denser mantle material sinks. This creates circular currents within the mantle, similar to how water boils in a pot. These are called convection currents.

* Dragging the plates: The convection currents exert a force on the tectonic plates that sit on top of the mantle. This force causes the plates to move, slowly but surely.

Here's a simple analogy: Imagine a pot of boiling water. The bubbles rising from the bottom are like the hot, less dense mantle material. The water sinking back down is like the cooler, denser mantle material. The heat from the stove is like the heat from the core. The surface of the water is like the tectonic plates. The bubbles push and move the surface of the water just like the convection currents push and move the tectonic plates.

So, the mantle and core play a crucial role in driving tectonic plate movement, which in turn causes earthquakes, volcanoes, and the formation of mountains and ocean basins.